An uprising by as many as 200 inmates at the maximum-security Marquette State Prison last night left five guards and one prisoner injured and three buildings on fire, authorities said.

A sixth guard was trapped inside the prison, but was removed unharmed by other prison personnel. Three of the guards were treated for unspecified injuries and were released from the hospital.

The uprising began about an hour after state police and guards moved to quell a disturbance at Southern Michigan Prison at Jackson, about 425 miles to the south, officials said.

Paul Maynard, administrative assistant to the warden, said the uprising at the 820-inmate Marquette prison started about 8:15 p.m. when between 150 and 200 inmates refused to return to their cells from the prison yard.

"We only can speculate it [the disturbance] stems from the general unrest that has been prevalent [at Jackson]," Maynard said.

One inmate was struck by shotgun pellets that apparently ricocheted into his thigh as he and other inmates tried to rush the laundry, Maynard said. It was not known whether the shots came from a guard tower or a riot squad outside the yard.

Jack Bergman, superintendent of a prison annex behind the main facility, said one guard suffered a broken bone in his face and four other received minor abrasions and contusions in scuffles with prisoners.

Firemen fought blazes at a prison garment factory, an inmate store and a school, while inmates still roaming the prison yard were watched by armed guards, Maynard said.

The prison houses Michigan's toughest inmates, those transferred from other state prisons because of disciplinary problems. Most have been conficted of violent crimes such as murder, rape and armed robbery, Bergman said.

At Jackson, rioting yesterday broke out for the second time in five days and left at least 21 people injured while fires caused heavy damage. About 1,000 of the prison's 5,600 inmates surrendered to guards at dusk, buckling to threats of tear-gassing.